Effect of Kharkhona on thermal comfort in the indoor space: A case study of Sistan region in Iran

Abstract

Achieving thermal comfort in buildings is one of the major concerns of studies in energy in buildings. One of the ways to achieve thermal comfort is to study and optimize vernacular solutions, especially in extreme climates. The Sistan region in the east of Iran is one of the special climatic regions in the world. The present study was conducted to achieve the thermal comfort conditions quantitatively updating one of the vernacular architectural techniques of the Sistan region called Kharkhona. Accordingly, the authors performed field measurements in two rooms with and without a Kharkhona on certain days and hours in the summers of 2019, 2020, and 2021. The results revealed that, on average, the thermal comfort index of PMV was 1.39 units lower, the PET index was 7.69 °C lower, and the SET* index was 3.98 °C lower than the room without a Kharkhona and throughout the day and night in the space with a Kharkhona. Moreover, based on the semantic range of PMV, PET, and SET*, it was determined that by creating a Kharkhona, the thermal perception of the room without Kharkhona was moderated primarily from the very unfavorable status of hot and very hot to much more favorable status of warm and comfortable with a Kharkhona. This change in this status is due to the presence of the Kharkhona and its positive climatic impacts, so it could bring the extreme climatic condition of the Sistan region closer to a comfortable thermal condition in a closed space.